1. Field of the Invention
The invention herein pertains to the field of substituted salicylideneimines, plant growth regulator compositions containing same and method of use, particularly to enhance pod set and increase yield in soybeans.
2. Description of the Prior Art
The novel compounds described and claimed herein belong to a generic class of compounds variously described as salicylideneimines, salicylidene anilines or formimidophenols. These compounds are Schiff bases prepared, typically, by the reaction of appropriately substituted aromatic amines and salicylaldehydes.
The most relevant prior art known to the inventor herein are U.S. Pat. Nos. 3,652,770 and 3,721,741, both to Rohr et al. The latter patent is a divisional application of the former, hence the disclosures of these patents are identical. Rohr et al disclose, in relevant part, certain salicylideneimines characterized by having a minimum of two halogen atoms fixed in the ortho and para (4 and 6) positions relative to the hydroxyl radical and, optionally, a third halogen in the meta (3) position on the benzyl moiety of the molecule bonded to an anilino moiety which may be substituted with at least one member selected from the group consisting of a halogen atom, CF.sub.3, NO.sub.2, CN, alkyl, alkoxy, SCN and a tertiary amino group. These compounds are used as active ingredients in phytopathogenic compositions for combatting harmful insects, acarides, nematodes, fungi and bacteria.
The disclosure of Rohr et al exemplifies, e.g., salicylideneimines which have either halogen or CF.sub.3 groups on the anilino moiety, but not both simultaneously and this together with the requisite limitation of a minimum of two halogen groups on the benzyl moiety is distinguished from the compounds herein which have but one halogen on the benzyl moiety and, in preferred embodiments, have both halogen and CF.sub.3 groups attached to the anilino moiety. The significance of these distinctions will be shown below in comparative tests of the Rohr et al compounds with those disclosed and claimed herein as plant growth regulator compounds--a utility not contemplated by Rohr et al. In most pertinent part, the U.S. Pat. No. 3,652,770 teaches the use of the pertinent compounds in quantities less than herbicidal for the express purpose of combatting phytopathogenic fungi and bacteria, insects, acarides, nematodes. The patentees in the U.S. Pat. No. 3,652,770 recognized that too great a quantity of the relevant compounds would kill plants and inhibit plant growth, but otherwise they failed to observe, appreciate, recognize and/or record any plant growth regulator effect of using the compounds for phytopathogenic animal life.
Other prior art less relevant than the above-mentioned Rohr et al patents include salicylideneimines which have monohalo substitution on the benzyl moiety and one or more halogens substituted on the anilino moiety, but no CF.sub.3 substitution as required herein. Exemplary of such art are: U.S. Pat. No. 3,478,097; Chemical Abstract (C.A.) 27, 1335 (1933); C.A. 50 854f (1956); C.A. 55, 5500-5501 (1961) and C.A. 56, 10012 (1962). None of these references disclose any plant growth regulator utility in general or soybean pod set enhancement and yield in particular. Use of a number of the compounds in said C.A. references in the regulation of plant growth is claimed in the inventor's said U.S. Patent Application Ser. No. 537,224.
Yet other less relevant prior art include the polyhalogenated benzylidene benzylamines or benzylidene phenylethylamines of U.S. Pat. No. 3,856,504 and the polyhalogenated benzylideneaniline derivatives disclosed in U.S. Pat. No. 3,862,833. Neither of these patents disclose salicylideneimines which have CF.sub.3 radical substitution on the anilino moiety. The relevance of these patents lies in the use of the disclosed compounds as plant growth regulators.
Finally, reference is made to U.S. Pat. No. 3,012,068, relevant only to the extent that the compounds therein are Schiff bases which are toxic to certain parasites and aquatic pests, e.g., insects, fungi, helminths, mites, bacteria, aphids, nematodes, snails and trash fish. Certain of the compounds in the '068 patent have utility for the control of weeds and inhibition of nitrification. The compounds of the '068 patent are characterized by the presence of a methylcarboxoyloxy radical and optionally other substituents and are thus-distinguished from the compounds of this invention.